我正在进行的程序允许用户输入文本并检查它是否是回文。输入按order（）排序，使用testPalindrome（orderedText）测试，然后使用showResult（Palindrome）显示结果。在保存回文时我的问题出现了。如果用户已经被验证为回文，则该用户应该能够保存输入。我认为如果禁用保存按钮直到输入测试为真，那将是有意义的。所以我把＆＃34; saveButton.config（state =＆＃39; normal＆＃39;）＆＃34;在showResult（Palindrome），但这不起作用。该错误表示＆＃34;全局名称＆＃39; saveButton＆＃39;没有定义＆＃34;，我可以看到原因。但是，我无法做到正确。我想知道是否有可能通过对这一行文本的一些补充来解决这个问题，或者我是否需要进行更彻底的修改。 （例如，我尝试将＆＃34; saveButton＆＃34;转换为全局变量，例如＆＃34; inputEntry＆＃34;但无论出于何种原因，我都无法使其工作。）
import Tkinter
root = Tkinter.Tk()
infoLabel = Tkinter.Label(root, text = 'Enter a text and check if it is a palindrome.', height = 12, width = 64, bg = 'green')
inputEntry = Tkinter.Entry(root, width = 64)
def main():
window()
Tkinter.mainloop()
def window():
root.title('Palindrome detector')
root.geometry('534x285+500+250')
infoLabel.grid(row = 0, rowspan = 1, column = 0, columnspan = 4, pady = 8, padx = 8)
inputEntry.insert(0, 'Enter text...')
inputEntry.grid(row = 1, rowspan = 1, column = 0, columnspan = 4, padx = 4)
verifyButton = Tkinter.Button(root, text = 'Verify', width = 7, command = order).grid(row = 2, column = 0, pady = 10)
saveButton = Tkinter.Button(root, text = 'Save', state = 'disabled', width = 7, command = save).grid(row = 2, column = 3)
def order():
Text_input = inputEntry.get()
orderedText = Text_input.replace(" ", "")
orderedText = orderedText.lower()
orderedText = filter(str.isalnum, orderedText)
if any(char.isalpha() or char.isdigit() for char in orderedText):
testPalindrome(orderedText)
else:
infoLabel.config(text = 'The input must contain at least one alphanumeric character.', bg = 'red')
def testPalindrome(orderedText):
Palindrome = True
i = 0
for char in orderedText:
if orderedText[i] == orderedText[-(i+1)]:
Palindrome = True
i += 1
else:
Palindrome = False
break
showResult(Palindrome)
def showResult(Palindrome):
if Palindrome == True:
infoLabel.config(text = 'Yes! "' + str(inputEntry.get()) + '" is a palindrome!', bg = 'green')
saveButton.config(state = 'normal')
else:
infoLabel.config(text = 'No! "' + str(inputEntry.get()) + '" is not a palindrome!', bg = 'red')
saveButton.config(state = 'disabled')
def save():
savePalindrome = inputEntry.get()
palindromes_file = open("Palindromes.txt", "a")
palindromes_file.write(savePalindrome + "\n")
palindromes_file.close()
infoLabel.config(text = '"' + str(savePalindrome) + '" has been saved to file.', bg = 'green')
saveButton.config(state = 'disabled')
if __name__ == '__main__':
main()
编辑：看完答案后，我跟着一本教科书，试图用课程重写整个事情。当然，可能会有任何数量的缺陷。我现在关心的是＃34; NameError：全球名称＆＃39; testPalindrome＆＃39;未定义＆＃34;。该错误按顺序（第7行）进行。我不明白为什么这条线和＃34;桥＃34;在order（self）和testPalindrome（self）之间突然出现了问题？
import Tkinter
import tkMessageBox
root = Tkinter.Tk()
class MyGUI:
def __init__(self, master):
self.master = master
master.title('Palindrome detector')
master.geometry('534x285+500+250')
self.infoLabel = Tkinter.Label(self.master, text = 'Enter a text and check if it is a palindrome.', height = 12, width = 64, bg = 'green')
self.inputEntry = Tkinter.Entry(self.master, width = 64)
self.infoLabel.grid(row = 0, rowspan = 1, column = 0, columnspan = 4, pady = 8, padx = 8)
self.inputEntry.insert(0, 'Enter text...')
self.inputEntry.grid(row = 1, rowspan = 1, column = 0, columnspan = 4, padx = 4)
self.verifyButton = Tkinter.Button(self.master, text = 'Verify', width = 7, command = self.order)
self.verifyButton.grid(row = 2, column = 0, pady = 10)
self.saveButton = Tkinter.Button(self.master, text = 'Save', state = 'disabled', width = 7, command = self.save)
self.saveButton.grid(row = 2, column = 3)
def order(self):
self.Text_input = self.inputEntry.get()
self.orderedText = self.Text_input.replace(" ", "")
self.orderedText = self.orderedText.lower()
self.orderedText = filter(str.isalnum, self.orderedText)
if any(char.isalpha() or char.isdigit() for char in self.orderedText):
testPalindrome(self)
else:
self.infoLabel.config(text = 'The input must contain at least one alphanumeric character.', bg = 'red')
def testPalindrome(self):
self.Palindrome = True
i = 0
for char in self.orderedText:
if self.orderedText[i] == self.orderedText[-(i+1)]:
self.Palindrome = True
i += 1
else:
self.Palindrome = False
break
showResult(self)
def showResult(self):
if self.Palindrome == True:
self.infoLabel.config(text = 'Yes! "' + str(self.inputEntry.get()) + '" is a palindrome!', bg = 'green')
self.saveButton.config(state = 'normal')
else:
self.infoLabel.config(text = 'No! "' + str(self.inputEntry.get()) + '" is not a palindrome!', bg = 'red')
self.saveButton.config(state = 'disabled')
def save(self):
self.savePalindrome = self.inputEntry.get()
self.palindromes_file = open("Palindromes.txt", "a")
self.palindromes_file.write(self.savePalindrome + "\n")
self.palindromes_file.close()
self.infoLabel.config(text = '"' + str(self.savePalindrome) + '" has been saved to file.', bg = 'green')
self.saveButton.config(state = 'disabled')
my_gui = MyGUI(root)
Tkinter.mainloop()
答案 0 :(得分：2)
您在函数中创建saveButton因此它是局部变量，并且在其他函数中不可用。您可以使用global saveButton中的window()将此变量设为全局变量。
def window():
global saveButton
# ....
saveButton = Tkinter.Button(...)
saveButton.grid(...)
-
正如凯文已经说过的那样：
这一行
saveButton = Tkinter.Button(...).grid(...)
将None分配给saveButton因为grid()始终返回None
使用
saveButton = Tkinter.Button(...)
saveButton.grid(...)
或
Tkinter.Button(...).grid(...)
如果您不需要saveButton变量。
答案 1 :(得分：0)
只需将调用放入验证功能，因为您希望每次它都是Palindrome时自动保存。并且您可以将值传递给函数，而不是第二次获取它。
def testPalindrome(orderedText):
## change to False so an empty string will not
## register as True
Palindrome = False
i = 0
for char in orderedText:
if orderedText[i] == orderedText[-(i+1)]:
Palindrome = True
i += 1
else:
Palindrome = False
break
showResult(Palindrome)
if Palindrome:
save(orderedText)
接下来学习课程，因为它解决了这些问题。网络上的许多教程之一http://python-textbok.readthedocs.org/en/latest/Introduction_to_GUI_Programming.html要使按钮全局化，请将其放在全局命名空间中（如inputEntry）。
root = Tkinter.Tk()
infoLabel = Tkinter.Label(root, text = 'Enter a text and check if it is a palindrome.', height = 12, width = 64, bg = 'green')
inputEntry = Tkinter.Entry(root, width = 64)
saveButton = Tkinter.Button(root, text = 'Save', state = 'disabled', width = 7, command = save)
saveButton.grid(row = 2, column = 3)